Effects of Feeding a Fermented Product on the Faecal Microflora and Egg Composition in Laying Hens

Abstract

The thesis studied the characteristics of a fermented product (FP) and the effects of the
FP on layers. Two experiments were conducted to achieve the objectives above.
Experiment I (Chapter IV) was conducted to evaluate the composition and consistency of
the finished fermented product (FP). The nutritive value and chemical compositions of
the product were evaluated after the process of fermentation. In parallel, microbiological
analyses, including lactic acid bacteria (LAB) and Enterobacteriaceae counts were also
performed. The fermentation process was repeated three times under the same running
conditions and using the same amounts of raw materials. The physical, chemical and
microbiological properties of FP obtained in this study showed that FP had consistent
chemical and microbiological characteristics. The presence of essential fatty acids (linoleic acid 24%, linolenic acid 1.1%, eicosapentaenoic acid 3.6%, docosapentaenoic
acid 0.7%, docosahexaenoic acid 2.0%) and a lime-flavored aroma represent additional
value-added attributes to the product.
Experiment II (Chapter V) was carried out to investigate the effects of feeding FP to
layers (Babcock B380) on faecal microflora, essential fatty acid and cholesterol levels in
eggs and plasma. A total of 96, 13-week-old Babcock B380 pullets were used in this
study. They were randomly assigned to four numerically equal groups with eight
replicates per treatments, three birds per replicates. All the birds were housed in
individual cages. Diet I (Cont), had no FP, Diet II (FP3) contained 3% (w/w) FP (30g
FP/kg diet), Diet III (FP6) contained 6% (w/w) FP (60g FP/kg diet) and Diet IV (FP9)
contained 9% (w/w) FP (90g FP/kg diet). The study lasted 16 weeks inclusive of two
weeks of adjustment period and a 14-week experimental period. Weekly feed intake and
egg production were recorded. Fresh faecal droppings were collected immediately and
cultured for LAB and Enterobacteriaceae and pH and VFA production were also
measured. Blood plasma cholesterol and fatty acid profiles were assayed at the end of the
experiment. Results obtained from this study showed that FP reduced (P<0.05) the faecal
Enterobacteriaceae and faecal pH. Higher (P<0.05) counts of faecal LAB in layers fed
with FP were observed. However, FP did not enhance (P>0.05) the egg production and
egg mass but (P<0.05) decreased the egg weight slightly. Feed intake and feed
conversion ratio (FCR, feed intake/egg mass) were not affected (P>0.05). However, egg
yolk cholesterol and plasma cholesterol concentrations were reduced (P<0.05) in the FP
fed laying hens compared to the control laying hens. The n-6: n-3 ratio in the egg yolk (control=7.9, FP9=6.1) and plasma (control=10.46, FP9=6.54) from the FP fed laying
hens were decreased compared to the control laying hens. Moreover, FP was able to
increase (P<0.05) the polyunsaturated fatty acid (PUFA): saturated fatty acid (SFA) ratio,
total n-3 PUFA and DHA concentrations in egg yolk and plasma. In summary, the results
of the dietary manipulation demonstrated the effectiveness of FP in shifting the
microflora composition of the avian GIT towards a beneficial balance. In addition, it has
the ability to increase the unsaturated fatty acid (UFA) content to a more healthy
proportion in eggs.